The present invention relates to light fixture cooling features, and particularly, to providing a light fixture with external surface features to facilitate cooling.
Managing the temperature of light sources in a light fixture is generally important to performance and longevity. This is particularly true with newer highly efficient lighting technology, for example, light sources such as LEDs or laser diodes. LEDs are generally selected to maximize the light output for a given power consumption at a reasonable cost. Because LED light sources operate at a much lower temperature than typical incandescent light sources, less energy is wasted in the form of heat production. However, LEDs tend to be more sensitive to operating temperature and lower operating temperatures also provide a much smaller temperature difference between the LED and the ambient environment, thus requiring greater attention to thermal management to transfer and dissipate any excess heat generated by the LED driver and emitter so that the design operating temperature for the components are not exceeded.
As temperatures rise, the efficacy of the LED is reduced, reducing the light output, and reducing the lifespan of the LED. LED lighting fixtures generally include both LED drivers and LED emitters. To facilitate dissipation of heat, convection, conduction, and radiation are available modes of heat transfer. For LED light fixtures, dissipation of heat by conduction is often provided by one or more LED packages being mounted on a heat sink. The heatsink is generally integral with or thermally coupled with the light housing, which often includes external cooling fins to further facilitate the dissipation of heat from the light fixture by convection and radiation.
Many prior designs seeking to address these concerns provides a set of fins forming vertical airflow channels extending radially around a light emitter and driver housing; however, the fins forming the airflow channels only abut vertical edges of the housing.
Therefore, it is desirable to provide a lighting fixture design in a unitary fixture that maximizes cooling by thermal convection for the light housing, including convection from horizontal surfaces of the housing, and shields the cooling features from as many viewing angles as practical. Additionally, for some lighting fixture designs, it is also desirable to minimize thermal conduction between emitter and driver housings.